1.) Field of the Invention
The present invention relates generally to agricultural implements such as cotton harvesters, and, more specifically, to a cross shaft row unit drive for such implements.
2.) Related Art
Implements such as cotton strippers include row units which are transversely adjustable on an auger housing connected to the harvester frame by a lift system. Each of the row units is driven by a complex arrangement of belts and sheaves mounted to jackshaft assemblies. A universal joint drive shaft connects drive to each unit. When the row units are lifted, a phase shift in the universal joint causes a torsional vibration in the drive and unit drive gear backlash so that noise and wear are increased. The acceleration and deceleration of all the rotating components also increase drive motor load. Much of the torque delivered by the drive motor is required to operate the drive components and overcome the negative effects of the phase shift. The previously available drive systems tend to be expensive and heavy and make row unit spacing changes difficult and time consuming. To move the units, the operator must move all of the jackshaft assemblies and change the belts since the belt length necessary is a function of the row unit spacing. Regular lubrication of the drive shafts is also required.
With some previous drive systems, the header supporting the row units can only be extended in one direction because of unique drive components on one side. As a result, to increase row capacity up to eight rows, a completely different header is necessary. The ability of custom operators and new purchasers of the implements to reconfigure the header for their particular row spacing requirements is limited. Reconfiguration of the header often requires different parts, and unnecessary original components supplied with the header are wasted.
Many current row unit drive systems include a drive belt for the cross auger wherein the drive sheave axis is at an angle of ninety degrees relative to the axis of the driven sheave. The drive therefore requires two idler pulleys to guide the belt around a corner. If the idlers are not precisely adjusted, the belt will come off. Belt life is significantly reduced because of the tortuous path.
It is therefore an object of the invention to provide an improved drive system for a harvester having transversely adjustable row units. It is a further object to provide such a system which overcomes most or all of the aforementioned problems.
It is another object of the present invention to provide an improved drive system for a harvester which is more compact, more cost effective and requires less maintenance than at least most previously available drive systems. It is another object to provide a system which is particularly useful for implements such as cotton strippers which have slidably adjustable row units and which may require frequent row unit spacing changes to accommodate different row spacings in the field.
It is yet another object of the invention to provide an improved drive system for row harvesting units on an implement such as a cotton harvester which eliminates belt and jackshaft changes when row spacing is changed and substantially reduces operator time to switch from one row spacing to another. It is a further object to provide such a system having reduced vibration, gear backlash and noise. It is another object to provide such a system which eliminates phase shift problems caused by universal joints and which takes less power to drive.
It is yet a further object of the invention to provide an improved drive system for row harvesting units which is more compact, less expensive, quieter, and more reliable and requires less power and maintenance than at least most previously available drive systems. It is a further object to provide such a drive system which facilitates configuration of the harvesting units in numerous patterns and for different row capacities, and which permits headers which support the row units to be extended on either side without need for parts changes.
It is a further object of the invention to provide an improved drive system for the row units of a cotton stripper having reduced noise output, less maintenance requirements and easier adjustability than at least most previously available systems.
A harvester drive system constructed in accordance with the teachings of the present invention includes a main hexagonal cross shaft which may be either continuous or include short shafts joined by couplers. Row units are pivotally connected to a cross auger housing for pivoting about the axis of the cross shaft and can slide on the housing and relative to the drive shaft to accommodate different row spacings. An individual slip clutch and a single bevel gear assembly, both of which slide on the cross shaft, drive each row unit and permit relatively easy transverse adjustments of the units. Each slip clutch can be set to the maximum torque requirement for the individual row unit drive unit so that unit protection is significantly increased over systems which have multiple drives on each clutch. A cross shaft extension is added if a single shaft is utilized and harvesting widths are needed which cannot be provided by the original shaft. The harvester header may be extended either to the left or to the right, or both, without modification of the individual row unit drives, and numerous row spacings can be accommodated quickly and easily. With the segmented shaft and couplers, each row unit has an identical shaft, and the couplers have spaced holes to accommodate the different row width. The standardized row unit shaft and coupler provide needed flexibility while minimizing the number of different parts required for various row spacings. Since the shaft stays with the row unit, changing the number of row units on the header and extending the width of the header are easier and there is less opportunity to misplace components.
Each row unit drive extends straight forward from the bevel gear, and a bearing mount extends from a row unit wall immediately adjacent the bevel gear. Universal joints and the associated lubrication requirements and phase shift problems are eliminated. Drive belts with tortuous paths are eliminated. The drive system is lighter and more compact, has better gear mesh and less noise output and is more reliable and cost effective than most previously available drive systems.
These and other objects, features and advantages of the present invention will become apparent to one skilled in the art upon reading the following detailed description in view of the drawings.